Object-plane to image-plane reduction is well known in optical scanning copiers, of which U.S. Pat. No. 3,614,222 is an example. Half-lens/mirror copiers, with and without reduction, are shown, for example, in U.S. Pat. Nos. 3,535,037; 3,543,289; 3,545,857; 3,572,927; 3,720,466 and 3,832,057.
Dual mode copiers are also known, wherein in a first or scanning mode a stationary original document is line-scanned by moving the appropriate optical elements, and wherein in the second or parked-optics mode, the optical elements are locked in a predefined position and the original is moved past a scanning line at a speed equal to the copier's photoconductor speed. U.S. Pat. Nos. 3,877,804; 3,900,258; 3,909,128 and 3,944,365 show such dual mode copiers of the half-lens/mirror type.
The present invention provides object/plane to image-plane reduction in a half-lens/mirror type copier wherein the difficult problem of off-axis orientation of the half-lens/mirror is solved by unique displacement of one of the scanning mirrors and of the half-lens/mirror. Reduction in an off-axis half-lens/mirror copier is provided by an analysis of such a copier, and the deduction that certain unexpected and unique movements are required in order to provide reduction.
The foregoing and other features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawing.